I am a little puzzled, I often see the same 360 fans push IMO very conflicting statements.
1) Regarding multi-platform games. Most agree there are PS3 exclusives providing technically (and artistically) well beyond what 360 games have provided so far. But most of the emphasis seems to be multi-platform games designed around the capabilities of the XBox 360 and ported onto the PS3 hardware. Usually both versions are about on par as should be expected with a game designed with the 360 in mind, sometimes the PS3 version shows micro advantages and more often the 360 version shows some micro advantages. In any case they usually have to be run side by side to notice any difference.
What I often see is a lot of turmoil about these usually small differences if to the advantage of the 360 version, but usually the performance of the PS3 version and everything else is pretty damn close in such cases still. So why so much turmoil, it's basically the same game?
2) Regarding high bitrate FullHD Blu-Ray movies vs 480p DVD or low bitrate "HD" movie downloads/streams (much lower bitrate than even broadcasted HD). Considering the above I just don't get it often many of the same people claim they don't see enough of a difference in picture quality? To me this sounds conflicting and IMO smells like bending arguments to suit fanboy interests.
P.S.
Regarding technical matters most of us probably know from past history, like from the Atari ST vs Amiga days that exclusives really show of a platform's capabilities. For example early Atari ST to Amiga ports often ran slightly better with the Atari ST original, despite the Amiga hardware being far more powerful and capable for these games (as similar Amiga exclusives clearly demonstrated). This was due to the differences of the two platforms and their 'game engines' having been designed around the ST's capabilities. However there were enough similarities between the ST and Amiga for various multi-platform developers to design games for both platform simultaneously, like for example Ocean's many cute games were almost identical while designed around the ST's capabilties (like the fun little game, New Zealand Story). This had to do with development costs, so their games did not do much parallax scrolling Amiga games were famous of, often did not use the Amiga soundchip to the fullest and were drawn in fewer colors than the Amiga was capable of amongst other differences between cross platform games and exclusives.